Sewing machine



Dec. 3@. 1 924 R. H. LAWSON SEWINGMACHINE ts-Sheet 1 7 Shee H 162 led Oct. 18, 1918 12% Ori inal Fi Dec. 39. 19241.

R H. LAWSON SEWING MACHINE Original Filed Oct. 18, 1918 7 s t -s t 2 R. H. LAWSON @ec. 3U, F924 SEWING MACHINE '7 Sheets-Sheet 3 Original Filed ct. l8, 1

R. H. LAWSON SEWING MACHINE WWW R. H. LAWSON SEWING MACHINE Original Filed Oct. 18, 1918 '7 s t wsh t 5 J22 W v Niki-ix Dec. 30. 1924.

R. H. LAWSON SEWING MACHINE Original Filed Oct. 18, 1918 7 s s t e R. H. LAWSON SEWING MACHINE 1918 v Sheets-Sheet 7 Original Filed Oct. 18,

Patented Dec. 30, 1924.

UNETED STATES ROBERT H. LAWSON, 0F

JERSEY.

terrace BEVERLY, MASSACHUSETTS, ASSIGNOR T0 UNITED SHOE IMA- CHINERY CORPORATION, OF PATERSON, NEW JERSEY,

A CORPORATION or New SEWING MACHINE.

Application filed October 18, 1918, Serial No. 258,677. Renewed November 23, 1923.

To all whom it may concern:

Be it known that I, ROBERT H. Lawson, a citizen of the United States, residing at Beverly, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Sewin Machines";'an'('l I do hereby declare the ibllowing to be a full, clear, and exact description ofthe invention such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to sewing machines, and more particularly to shoe sole sewing machines of the well known McKay type.

In shoe sole sewing machines of the McKay type at present in common commercial use, the horn which carries the looping device or whirl is vertically fixed, and the presser foot is movable with relation to the horn to compensate for varying thicknesses of work. In these machines, in order that the needle may be threaded properly and the stitches be formed and tightened in, a uniform manner in each cycle of operation of the machine, it is essential that there be a certain amount of dwell in the needle motion at the limit of eachwork piercing stroke of the needle, and that the limit of this stroke of the needle be fixed, while the limit of the loop drawing stroke thereof be varied in accordance with changes in the vertical position of the presser foot due to variations in the thickness of the work.

The objects of the present invention are to improve the needle actuating mechanism and certain other mechanisms and parts of McKay shoe sole sewing machines with a view of making them simpler and more durable in construction, and smoother running and more efiicient in operation.

With these objects in view the present invention consists in certain features of constructions and combinations of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

The several features of the present invention will be clearly understood from an inspection of the accompanying drawings, in which;

Figure 1 is a view in side elevation of a machine embodying a preferred form of the invention;

Fig. 2 is a detail view in perspective of a part of the cast-off mechanism;

Fig. 3 is an enlarged side View, partly in section, of the head of the machine;

Fig. 4 is a detail View of a part of the mechanism for varying the limit of loop drawing strokes of the needle;

.Fig. 5 is a plan view of the head of the machine;

Fig. 6 is a detail sectional view, partly in elevation, of a control rod for the stop mo tion mechanism of the machine;

Fig. 7 is an enlarged front view, partly in section, of the head of the machine; i

Fig. 8 is a vertical sectional view taken on the line 88 of Fig. 5;

Figs. 9 and 10 are detail views illustrating the operation of the needle actuating mechanism;

Figs. 11 and 12 are sectional views taken on the line 1111 of Fig. 3 illustrating the work feeding mechanism in different positions;

Fig. 13 is a sectional view taken on the line 1313 of Fig. 11; Fig. 14 is a sectional view,'partly broken away to save space and partly in elevation, taken on the line i k-14 of Fig. 7 and I Fig. 15 is a view in horizontal section taken through the base of the machine.

The machine illustrated in the drawings comprises the usual vertically reciprocating straight hook needle indicated at 1, which during each cycle of operations is projected through the work into position to receive the thread from a looping device located in the tip of the horn. The cast-oft for preventing the previously formed loop from catching in the hook of the needle as the needle is retracted is indicated at 2. The work is supported during the sewing operation by the horn 3, which in the present embodiment of the invention is vertically fixed, but is arranged to rotate in the usual manner. The work is engaged between the upper surface of the tip of the horn and the presser foot 4 which is arranged for vertical movement to accommodate work of varying thicknesses. The work is fed at intervals during the operation of the machine by the feed point 5, which is projected into the work and is then advanced in the direction of the seam to feed the work.

The parts above referred to are substanchine.

tially the same in construction and mode-of operation as the corresponding parts of certain other McKay sewing machines, such for example, the machine illustrated and described in the patent to Meyer N 0. 1,177,581, dated March 28, 1916.

The presser foot 4 is secured to the lower end of a bar 6 which is mounted to slide vertically in suitable guides on the frame of the machine. The lower portion of the presser foot bar slides in a guide in the forwardly projecting portion 8 of the frame,

and the upper portion of the bar 6 is re-.

duced to form a cylindrical extension or rod 10 which is arranged to slide in a hearing 12 in the bracket 14 on the frame. The presser foot is held downon the work by the downwardly spring pressed arm 16 which acts on the upper end of the bar 6 through a link 18 (Figs. 3, 5 and 7). The arm 16 is provided with the hub 20 pivoted on a sleeve 22 which is mounted on a stud 24 projecting from the frame of the ma- The arm 16 is pressed downwardly by a heavy spring 26 coiled about the hub 20 and having one end secured to a flange 28 on the sleeve 22 and having its other end bearing on the top of the arm. To adjust the tension of the spring 26, the sleeve 22 is adapted to be rotated on the stud 24 to wind up the spring, and this is permitted by loosening a nut 30 threaded on the end of the stud which normally clamps the sleeve from rotation between a washer 32 on the stud and the bracket from which the stud projects.

In the illustrated machine the presser foot is retracted or lifted from the work against the action of the spring 26 by a rock-shaft 34, through an arm 36 secured to the forward end of the rock-shaft and having its end bifurcated toengage a stud 38 on the presser foot bar. The rock-shaft 34 is actuated to retract the presser foot, just as the needle 1 leaves the work on its upstroke as usual, by means of a cam 40 carried by the main shaft 42 of the machine head. through a cam roll 44 on the upper end of a lever 46 which is pivoted on the rock-shaft and is operatively connected therewith through a friction clutch 48 (Fig. 8) and an arm 50 carried by the rock-shaft. The friction clutch consists of a roll 52 which is sustained in engagement with a friction surface 54 formed on the lever 46 and a friction surface on the end of the arm 50 which is concentric with the rock-shaft 34, by means of a spring pressed plunger 56 carried the lever 46. At the proper time during, the downstroke of the needle, the friction clutch 48 is released which permits the presser foot by the action of its spring to be pressed into engagement with the work. The friction clutch is released by means of a finger 58, pivoted on the lever 46,

which is swung on its pivot to force the roll 52 outwardly from clutching engagement with the lever 46 and arm 50, by the engagement therewith of a cam roll 60 carried by an arm 62 secured to a shaft 64. The arm 62 is moved to cause its roll to thus actuate the finger-58 by-a cam 68 secured to the main shaft 42. 4

In order to enable the operator to raise the presser foot when the machine is at rest, the rock-shaft 34 through which the presser foot is raised, has a segmental gear 70 secured thereto (Fig. 8) which meshes with a segmental gear 72 formed on one arm of a lever 74 pivoted on the frame, and the other arm of said lever is connected through a rod 76 with a treadle 77 of the usual foot treadle mechanism 78 (Figs. 1 and 15). It will be seen that bydepressing the rod 76 the rock-shaft 34 will be actuated in the direction to raise the presser foot.

In the illustrated machine the needle motion is accelerated during substantially the first half of both its work piercing and loop drawing strokes and is retarded during the remaining portion of its strokes, in such a manner that the needle motion is exceptionally smooth and free from vibration, and the work is cleanly pierced by-the needle and the stitches are tightly formed. Pro-- vision is also made whereby the needle motion has a relatively considerable amount of dwell at'the limit of each work piercing stroke to ensure the proper threading of the needle by the looping device. The needle actuating mechanism for affecting such movement of the needle, comprises a crank 80 (Figs. 3 and 7 on the main shaft 42 which is connected by a pitman 82 with the knee of a toggle 83 having the outer end of one arm 84 pivoted on a stud 86 and the outer end of its other arm 88 pivoted on the shorter arm 90 of a bell crank lever 92. The lever 92 is pivoted on a shaft 94 journaled in bearings in.the frame of the machine and the end of its longer arm 96 is pivoted on a transversely sliding block 98 mounted on the needle bar 99 which is mounted to slide in bearings at the front of the frame of the machine. It will be seen that by this improved needle actuating mechanism the desired dwell in the needle motion is effected both by the crank 89 and the toggle 83 approaching their dead centers as the needle approaches the limit of its work piercing stroke.

The needle actuating mechanism is adapted to be automatically adjusted to vary the limit of the loop drawing stroke of the needle in accordance with changes in the ver- I an arm 100 pivoted on the frame of the machine, with the axis of its pivot in a position such that the axis of the knee of the toggle will be'in coincidence therewith when the needle is at the limit of its work piercing stroke. By pivotally adjusting the arm 100 and consequently the position of the stud 86, the limit of the loop drawing strokes of the needle obviously will be adjusted accordingly without varying the limit of the work piercing strokes of the needle. The proper adjustment of the arm 100 to vary the limit of the up-strokes of -the needle in accordance with variations in thickness of the work, is effected through mechanism connecting the arm 100 with the v rock-shaft 34 which is connected with the till presser foot through the arm 36 as hereinbefore described. This connection between the arm 100 and the rock-shaft comprises a link 102 having one end pivoted on the stud 86 and its other end pivoted on an arm 104 which is formed on a sleeve 106 pivotally mounted on the rock-shaft 34 and is adapted to be operatively connected therewith through a clutch 108 (Figs. 3, 4 and The clutch 108 consists of a clutch member 110 formed on the sleeve 106 which is pressed toward operative engagement with a clutch member 112 secured to the rockshaft 34, by a coiled spring 114. The sleeve 106 is held from movement with the shaft by a friction clutch 116 which consistsof a split collar held in clutching engagement with the sleeve 106 by an expansion spring 1 18 on a bolt 120 which extends through lugs 122 formed on the ends of the split collar. The clutch 108 is so constructed that the amount which the rock-shaft 34 is rotated by the downward movement of the presser foot determines the position of the sleeve 106 on the rock-shaft which, through the arm 104 and link 102, adjusts the position of the link 100 through which the needle ac tuating mechanism is adjusted as above described. As the amount the rock shaft is rotated by the downward movements of the presser foot is dependent upon the thickness of the work, it will be seen that the upstrokes of the needle will be varied thereby in accordance with the variations in thickness of the work. In order to permit such adjustment of the sleeve 106 on the rockshaft by the movement of the latter, the friction clutch 116 is released just before the downstroke of the presser foot. which permits the proper positioning of the sleeve by the engagement of shoulders 126 and 128 on the members of the clutching device 108 while the presser foot is in engagen'ient with the work. The friction device 116 is then locked and retains the sleeve and consequently the arm 100 in position until the next down-stroke of the presser foot. As shown in Fig. 4 there is a sutlicient amount of lost motion between the members of the clutch 108 so that the position of the sleeve 106 is unaffected by the upstroke of the presser foot. The friction clutch 116 is released by the cam 68, previously referred to, which, through the cam roll 60, arm 62 secured to the shaft 64 and arm 130 secured to said shaft, depresses the lower lug 122 of the friction clutch against the action of the clutch spring 118. In Fig. 9 of the drawings is shown, by broken lines, relative positions of parts of the needle actuating mechanism at the limit of a loop draw ng stroke of the needle; and by full lines relative positions of such parts at the limit of a work piercing stroke of the needle and after the arm 100 has been adjusted, as above described, to a different position from that shown by broken lines in order to adjust the limit of this stroke of the needle in accordance with an increase in thickness of the work. It will be, seen that such adjustment of the arm 100 from the position shown by broken lines to the position shown by full lines will cause the length of the next succeeding up-stroke of the needle to be greater than the previous up-stroke indicated by the broken lines. In Fig. is shown by broken lines the relative positions of parts of the needle actuating mechanism at the limit of an up-stroke of the needle and by full lines the relative positions of such parts at the limit of the next succeeding up-stroke of the needle and after the needle actuating mechanism has been adjusted to a decrease in thickness of the work.

The mechanism in the illustrated machine for actuating the usual cast-off 2 is simple and durable in construction and highly efiicient in operation. The cast-offis mounted to slide in a. groove in the needle bar and is actuated in the usual timed relation to the needle through a bar 134, to the lower end of which the upper end of the castoff is secured. The bar 134 is actuated by movement of the needle bar through a pin 136 at its upper end -which extends through a vertical slot 138 in the needle bar and through the bifurcated end of a link 140, the upper end of which is pivoted to the end of an arm 142 having a split hub 144 which is frictionally retained in position on a bearing 146 (Fig. 5) on the frame of the machine by a coiled spring 148 mounted on a bolt which extends through ears on the hub. During the down-stroke of the needle bar the pin 136 is engaged by the upper end of the wall of the slot 138, and the cast-01f is thereby carried down through the previously formed loop in the thread and into engagement with the work. The friction arm 142 retains the cast-off in the positions to which it is moved by the needle bar. Relative movement of the needle bar and cast-off is permitted after the cast-01f engages the work during the down-stroke of the needle, by a slot 150 in the cast-ofl bar 134 through which'the pin 136 extends and by a coiled spring 152 having one end secured to the pin and its other end secured to the bar 134. The cast-off is raised at the proper time during the upstroke of the needle by the engagement of the lower end wall of the slot 138 in the needle bar with the pin 136.

The feed point actuating mechanism is extremely simple in construction and highly eflicient in operation, and has been designed particularly to withstand the severe strain due to the actuation of the feed point with the necessary force and rapidity. Referring to Figs. 7, 11, 12 and 13, the feed point 5 is carried by a lever or carrier 156 having a pivot and guide pin 158, the ends of which engage cam slots 160-160 in the vertical walls of a recess near the lower extremity of the presser foot bar 6, and said carrier is actuated by an oscillatory arm 162 through a link'164 having one end pivoted on the lower end of said oscillatory arm and the other end pivoted on the guide pin. The feed point is pressed downwardly by a coiled spring 166 having one end secured to the outer end of the lever 156 and its other end secured to the oscillatory arm 162. and such downward movement of the feed point is limited by the engagement of the rear portion of the carrier 156 with the link 164. As the presser foot is raised, which occurs just as the needle leaves the work on its loop drawing stroke. the feed point is advanced by the arm 162 and is projected into the work by the cam slots 160 against the action of the spring 166. By the continued advancing movement of the carrier, after the feed point has been thus projected into the work,

the work is fed the desired amount. In similar mechanisms heretofore devised for actuating the feed point. the amount which the feed point is projected into the work during the feeding movement thereof is limited by the engagement of the carrier with a memher in sliding engagement therewith, and as the feeding of the work causes the carrier to exert considerable pressure on such memher, it has been found in practice that these parts soon wear to such an extent that the feed point is thereby permitted to be projected so far into the work as to be objectionable. In the illustrated machine, this objectionable feature of prior mechanisms has been overcome by utilizing the link 164 which moves with the carrier during the feeding movement, as the stop to limit the amount the feed point is projected into the work. After the feeding movement the carrier is retracted by the arm 162 which disengages the feed point from the work, as shown in Fig. 12 and brings the feed point back to its normal position (Fig. 11). The oscillatory arm 162 is pivoted on the frame of the machine and is actuated .by the grooved cam 168 (Fig. 8) carried by the main shaft 42 which is engaged by a cam roll on the end of an arm 170 secured to the shaft 94. The arm 162 is connected to an arm 172 (Fig.7) secured to the shaft 94, by a link 174.

During the sewing operation, the machine illustrated in the drawings is driven by means of a belt 176 (Fig. 1) passing about a pulley 178 carried by a driving shaft 180 located at the base'of the machine, which connects this pulley with' a pulley 182 clutched to the main shaft 42 by a clutch member 184 secured to the main shaft. The pulley 182 is brought into engagement with the clutch member 184 through a sliding sleeve 186 (Fig. 3) confined on the shaft 42 between the hub of the pulley 182 and a washer 188. The washer 188 is secured by a nut 190 to a sliding control rod 192 which extends into an axial bore in the main shaft 42. A collar 194 mounted to slide on the shaft 42 is secured to the forward end of the rod 192 by a pin 196 (Fig. 6) which extends through slots 198 in the shaft 42. The collar 194 is provided with an annular recess which is engaged by a stud or roll 200 mounted on the lower arm of a bell crank lever 202 pivoted on the frame of the machine. The bell crank lever is rocked to shift the pulley 182 into engagement with the clutch member 184 by depressing a rod 204 which connects the bell crank lever with a treadle 206 of the foot treadle mechanism 78. This movement of the bell-crank lever 202, through a link 208, shifts an arm 210 forwardly to bring a roll 212 thereon out of locking engagement with a disk 214 secured to the main shaft 42. The arm 210 is mounted to slide on the shaft 34 and is retained in its retracted position by the engagement of a latch 216 pivoted on the hub of the arm. with a stud 218 on the frame of the machine. Upon releasing the treadle 206 at the completion of the sewing operation, the control rod 192 is moved rearwardly which, through a collar 217 secured to the control rod by a pin extending through slots in the main shaft 42, disengages the high speed pulley from the clutch member 184. This movement of the con trol rod is effected by the bell crank lever 202 which is swung on its pivot by the upward movement of the treadle rod 204. The treadle rod is carried upwardly upon releasing the treadle 206 by a coiled spring 219 having one end secured to the rod and iths other end secured to the frame of the ma c me.

The high speed pulley drives the machineat a high rate of speed and in order to stop the machine without danger of injuring its with the clutch member 184 after the high speed pulley is thrown out of engagement with the clutch member, and at a predetermined point in a cycle of operation of the machine. The low speed pulley first acts to reduce the speed of the machine and then acts to drive the machine at a low speed in the same direction as the machine is driven by the high speed pulley. After the machine is acted upon by the low speed pulley for a predetermined length of time, this pulley is thrown out of clutching engagement with the main shaft 42 and mechanism. acts to stop the machine at a predetermined point in its operation.

The low speed pulley which is indicated at 220 is loosely mounted on the main shaft 42 and is driven through a belt 222 (Fig. 1) by a pulley 224 carried by the driving shaft 180. The low speed pulley 220 is shifted into engagement with the clutch member 184 by the control rod 192 through the engagement of its collar 194 with the end of a forwardly extending sleeve 225 on said pulley. The movement of the control rod 192 upon the release of the treadle rod 204, while suflicient to disengage the high speed pulley from the clutch member is not sufficient to cause the engagement of the low speed pulley and clutch member. The additional rearward movement of the control rod required to shift the low speed pulley into engagement with the clutch member is effected through a lever 226 having its rear end pivoted on the treadle rod 204 and centrally pivoted on a pin 227 secured to the vertical arm of the bell crank lever 202. The upward movement of the treadle rod 204 to disengage the high speed pulley 182 swings the forward end of the lever 226 downwardly to cause a notch 228 therein to be brought into engagement with a stud 238 on the upper end of a lever 240 having its lower end pivoted on the frame of the machine. The lever 240 is actuated by a cam roll thereon which engages the cam groove in a cam 242 carried by the main shaft 42. At a predetermined time in the rotation of the shaft 42 the cam 242 through the lever 240-shifts the lever 226 rearwardly which,

through the bell crank lever 202 imparts the.

required rearward movement to the control rod 192 to shift the low speed pulley into operative engagement with the clutch member 184. This movement of the bell crank lever 202 is effected through an expansion spring 244 disposed between the forward end of a slot in the lever 226 and a block 246 mounted in sliding engagement with the top and bottom walls of the slot. The block 246 serves as a pivot bearin for the lever 226 on the pivot pin 227.

During the effective operation of the machine, the roll 212 is held out of engagement with the locking disk 214 by the engagement of the latch 216 with the stud 218 as hereirrbefore described. Near the limit of the movement of the bell crank lever 202 to clutch the low speed pulley to the shaft, the latch 216 is disengaged from the stud 218 which permits the roll 212 to be brought into engagement with the face of the locking disk by a spring 248 having one end secured to the hub of the arm 210 which carries the roll 212 and its other end secured to the frame of the machine. The

,latch 216 is released from the stud 218 at the proper time by the engagement of a pin 250 on the forward end of the link 208 with a member of the latch.

After the low speed pulley acts to drive the shaft 42 for a predetermined length of time, the cam'242 througlrthe lever 226 shifts the control rod 192 forwardly a sufficient distance to cause a collar 252 secured thereto by a pin extending through slots in the shaft 42, to throw the low speed pulley out of clutching engagement with the shaft. To stop the rotation of the shaft, a recess 254 in the locking disk 214 is brought into registry with the roll 212 which allows the roll to be brought into locking engagement with the disk by the action of the spring 248. The roll is pressed inwardly against the bottom of the recess by a coiled spring 256 having one end secured to the arm 210 and its other end secured to the frame of the machine. In order to prevent the machine from being stopped too suddenly by the engagement of the roll 212 with the recess in the locking disk 214, the walls of the recess flare outwardly and the spring-248 permits a certain amount of yielding vibratory movement between the roll and the shaft until the shaft is brought to rest, at which time the roll is seated in the bottom of the recess in the locking disk.

The driving and stopping mechanism above described forms the subject matter of a seperate application filed February 7, 1919, Serial No. 275.610 on which Patent No. 1,482,801 issued February 5. 1924.

While the features described above are well adapted for use in the type of machine illustrated in the drawings, it is to be understood that except as defined in the claims certain features of the invention are not limited to use in a machine embodying any or all of the other features.

The nature and scope (if the present invention having been indicated, and a machine embodying the several features of the invention in their preferred form having been specifically described, what is claimed 1s:

1. A sewing machine having, in combination, a needle bar, a crank, a toggle, a pitman directly connecting the crank with the knee of the toggle, and means connect= ing the outer end of one arm of the toggle with the needle bar whereby the rotation of the crank effects the actuation of the needle.

2. A sewing machine having, in combination, a needle, a needle bar, a crank, a toggle, a pitman directly connecting the crank with the knee of the toggle, and a bell crank lever having the end of one arm pivotally connected to the outer end of one arm of the toggle and the end of its other arm pivoted on the needle bar whereby the rotation of the crank effects the actuation of the needle.

3. A sewing machine having, in combination, a needle, a needle bar, a crank, means for rotating the crank, a toggle, a pitman connecting the crank with the knee of the toggle, means connecting the outer end of an arm of the toggle with the needle bar whereby the rotation of the crank effects the reciprocation of the needle, and means con-trolled by variations in thickness of the work for adjusting the position of the pivot of the'outer end of the other arm of the toggle to vary the limit of a stroke of the needle.

4. A sewing machine having, in combination, a needle, a needle bar, mechanism including a toggle and a bell crank lever directly connecting the needle bar and the outer end of one arm of the toggle for reciprocating the needle bar. a fixed but a'djustable pivot for the other arm of the toggle, and means controlled by the thickness of the work for adjusting said pivot to vary the limit of a stroke of the needle bar.

5. A sewing machine having in combination, aneedle, aneedle bar,acrank, means for rotating the crank, a toggle, a pitman connecting the crank with the knee of the toggle, a pivoted arm having its outer end pivotally connected to the outer end of onearm of the toggle and corresponding in length to the length of said arm of the toggle, means connecting the outer end of the other arm of the toggle with the needle bar whereby the rotation of the crank effects the reciprocation of the needle, and means controlled by variations in thickness of the work-for adjusting the position of said pivoted arm about its pivot whereby the limit of a stroke of the needle is varied.

6. A sewing machine having, in combination, a presser foot, a rock-shaft connected therewith, a needle, a needle bar, a crank, a toggle, a pitman connecting the crank with the knee of the toggle, a pivotedvarm havin its outer end connected to the rock-sha t and to the outer end of one arm of the toggle and corresponding in length to the length of said arm of the toggle, means connecting the outer end of the other arm of the toggle to the needle bar whereby the rotation of the crank effects the reciprocation of the needle, and means actuated through the presser foot and rock shaft for adjusting the position of said pivoted arm about its pivot to vary the limit of a stroke of the needle in accordance with variations in thickness of the work.

7. A sewing machine having, in combina tion, a needle, a needle bar, mechanism including a link for reciprocating the needle bar, a pivoted arm having its outer end pivotally connected to one end of the link and corresponding in length to the link, said arm adapted to be adjusted to vary the limit of a stroke of the needle, a resser foot, a work support, means inclu ing a rock shaft for reciprocating the presser foot toward and from the work support, a yielding connection between the rock-shaft and arm whereby the arm is adjusted in accordance with the vertical position of the presser foot when in engagement with the work, and means for retaining the arm in position during the retracting stroke of the presser foot.

8. A sewing machine having, in combination, a needle, needle actuating mechanism, a presser foot, means including a rock shaft for reciprocating the presser foot, a sleeve pivotally mounted on the rock shaft, means connecting the sleeve with the needle actuating mechanism whereby the adjustment.

of the sleeve on the rock-shaft adjusts the limit of a stroke of the needle, a spring coiled around the rock shaft and-forming a yielding connection therewith whereby the sleeve is adjusted in accordance with the vertical position of the presser foot when in engagement with the work, a clutching device surrounding thesleeve to retain the sleeve in A position during the retracting stroke of the presser foot, and means for releasing the clutching device during a portion of the work engaging stroke of the presser foot.

9. A sewing machine having, in combination, a needle, a needle bar, a crank, means for rotating the crank, a toggle, a pitman connecting the crank with the knee of the toggle, means connecting the outer end of an arm of the toggle with the needle bar whereby the rotation of the crank effects the vertical reciprocation of the needle, and means controlled by variations in thickness -of the work to adjust the position of the outer end of the other arm of the toggle vabout an axis which coincides with the axis of the knee of the toggle when the needle is at the limit of its down-stroke whereby the limit of the up-stroke of the needle is changed.

10. A sewing machine having, in combination, a work support, a presser foot, means for retracting the presser foot from the work support and sustaining it in a retracted position comprising a rock shaft, an arm secured to the rock shaft, having a friction clutch surface formed thereon, a cam, a lever pivotally mounted on the rock shaft actuated by the cam and having a friction clutch surface formed thereon, a clutch member interposed between the friction clutch surfaces to co-operate therewith to clutch the lever and arm together when moved in one direction and to disconnect the arm and lever when moved in the opposite direction, means for thus actuating the clutch member, and means for moving the presser foot toward the work support when the arm and lever are disconnected.

11, A sewing machine having, in combination, a work support, a presser foot, a rock-shaft connected to the presser foot, a cam actuated arm pivoted on the rock-shaft, a'clutching device to operatively connect the arm and rock-shaft to retract the presser foot, means comprising a member mounted on the arm for releasing the clutching device, and means for moving the presser foot toward the work-support when the clutching device is released.

12. A sewing machine having, in combination, a needle, a needle bar, mechanism for reciprocating the needle bar, acast ofi',afric tion device tending to hold the cast-off stationary, and means including a pin extending through a vertical slot in the needle bar and connected to the cast-off for actuating the cast-oil.

13. A sewing machine having, in combination, a work support, a presser foot, a presser foot bar, a feed point, a carrier for the feed point pivoted on the presser foot bar, means including a link for actuating the carrier to project the feed point into the work and to feed the work, and means to press the carrier and link together during the feeding movement of the carrier whereby the link serves as a stop to limit the amount the feed point is projected into the work.

14. A sewing machine having, in combination, a presser foot, a presser foot bar, a feed point, a carrier for the feed point pivoted on the presser foot bar, means for actuating the carrier to project the feed point into the work and to feed the work, and a stop movable with .the carrier during its feeding movement to limit the amount the feed point is projected into the work.

15. A sewing machine having, in combination, a needle, a needle bar, needle actuating mechanism comprising a crank, a toggle, a pitman connecting the crank with the knee of the toggle, means connecting the outer end of one arm of the toggle with the needle bar whereby the rotation of the crank effects the actuation of the needle, and means for adjusting the needle actuating mechanism to vary the extent of the move ment imparted to the needle in accordance with variations in the thickness of the work.

16. A sewing machine having, in combination, a needle, a needle bar, mechanism for reciprocating the needle bar, a cast-off, a bar on which the cast-ofi is mounted, a pin extending through a slot in the needle bar and a slot in the cast-off bar, a friction device tending to maintain the pin stationary, and a spring tending to move the cast-ofl' bar downwardly relatively to the pin.

17. A sewing machine having, in combination, a needle, needle actuating mechanism comprising a single crank, and connections between the crank and the needle comprising an arrangement of links and levers, a presser foot, and connections between the presser foot and the needle actuating mechanism whereb the needle stroke is varied in accordance with variations in the thickness of the work.

18. A sewing machine having, in combination, a needle, needle actuating mechanism comprising a single crank and connections between the crank and the needle, a presser foot, and means acting to adjust the needle actuating mechanism to vary the needle stroke in accordance with variations in the thickness of the work.

ROBERT H. LAWSON. 

